Trash screen



March 9, 1954 C, 1 BENNER, JR 2,671,563

March 9, 1954 c. J. BENNER, JR 2,671,563

TRASH SCREEN Filed May 2, 1951 7 Sheets-Sheet 2 .mmm

* IANVENTOR" March 9, 1954 c. J. BENNER, .1R

TRASH SCREEN 7 Sheets-Sheet 3 Filed May 2, 1951 March 9, 1954 c. J. BENNER, JR

TRASH SCREEN 7 Sheets-Sheet 4 Filed May 2, 1951 INVENTOR Zl/efJm/Mgef March 9, 1954:*-

c. .1. BENNER, JR 2,671,563

TRASH SCREEN Filed May 2,1951 7 Sheets-Sheet 5 INVENTOR March 9, 1954 C, J, BENNER, JR 2,671,563

TRASH SCREEN Filed May 2, 1951 7 Sheets-Sheet 6 f WM5 INV ENTOR March 9 1954 c. J. BENNER; .1R 2,671,563

TRASHSCREEN Filed May 2, 1951 '7 Sheets-Sheet '7 INVENTOR ATTORNEY Patented Mar. 9, 1954 UNITED STATES PATENT orme TRASH SCREEN Charles I. Benner, Jr., North Hills, Pa., assigner to-Linl-Belt Company, a corporation of. Illinois Application May 2, 1951, Serial N o. 224,100

(Cl. 21m-1,76)

1g Claims. 1

This invention relates to newf and useful im* provements in trash screens, and deals more specically with mechanically cleaned, vertical bar type trash screens.

The use of bar type screens for the removal of trash and other large solids from water and sewage under treatment has become increasingly widespread in recent years and serves to prevent damage to the mechanical equipment of water, sewage and industrial waste treatment plants through which the Water subsequently ilows. In such installations, a large portion of the screen itself issubmerged in the water or sewage and the screen cleaning rake and its carrier chain, or similar device must, therefore, pass below the surface of the water through the lower portion of its path of travel. Access to the submerged portions of the screen and cleaning de vice is diifncult and necessitates suspending operation of the treatment unit so that it is most important that the screen and cleaning device be possessed of long wearing characteristics With a minimum o f maintenance. It isalso important that the screen and cleaning device` be so arranged as to substantially preclude the possibility of failure due to jamming orf-otherwise stopping movementof the cleaning device,

The primary object of the invention isto provide a vertical bar type trash screen which is so constructed as to practically eliminate any chance of the bar cleaning mechanism becoming jammed or the bars being clogged with loating material, and which is so vertically positioned or arranged as to minimize the amount of horizontal space required for its installation and the friction developed between the relatively movable cleaning rakes and screening bars and between the rake carrying chains and their guides with the result that wearing of parts andpower consumption are substantially reduced.

A further object` of the invention is the proe vision of a novel way of mounting and supporting the vertical bars which form4 the screening rack.

A further object o f the invention isto provide a novel way of mounting the vertical bars which formA the screening rack and supporting their upper end portions in such a manner as to permit movement of the bar cleaning rakes along the entire lengths of the bars without inter'-L ference between the rakes and supporting mechanism.

A still further object of the invention is to Provide 9a Veltal br WD@ 351.1 Scl'eel Which iS. SQ Gollstlllcteq that th?- Qlllg @39S are laterally supported while engaging the screening bars and will in turn afford lateralsupport for the bars.

Still another object of the invention is to provide a vertical bar type. trash screen, the clean? ing mechanism of which is so constructed as to afford lateral support for the bars while removing the refuse therefrom, to carry the refuse Ifrom the hars. to a point of discharge inY such a manner as to eliminate any accidental release of the refuse to the screened water, and totau-v tomatically and positively remove the refuse from the cleaning mechanism at. the point of discharge.

A still further object of the invention is to provide a verticalbar type trash` screen, the bars of which aremounted and supported in a novel manner and the cleaning mechanism of which is so constructed that. its submerged portion lies substantially entirely within the water that has passed through the screening rack.

A further object of the invention is to provide a trash screen which is so constructed that, the top of the screening rack may terminate at any desired distance below the trash discharge housing to permit such trash screens to be readily adapted for installation at different locations where the distance between the floor and the maximum Water level may vary.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like reference characters are employed to designate like parts throughout the same,

Figure 1 is a top plan View of a trash screen embodying the invention,

Figure 2 is a vertical sectional view taken on line 2-2 of Fig. 1,

Figure 3 is a vertical sectional View takenlon line 3f-3 of Fig. 2,

Figure 4 is a horizontal sectional view taken on line 4 4 of Fig. 2,

Figure 5 is a horizontal sectional View taken on line 5,-.5 of Fig. 2,

Figure 6 is a, horizontal sectional view talen on line -ii of Fig. 2,

Figure '7 isa fragmentary sectional view tak,- en on line 6-6 of Fig. 2 and showingA one. clean,- ingrake in its screen cleaning position,

Figure 8 1S a fragmentary perspective View showing a part of the screen bar supporting Structure,

view showing the coaction of the rake cams and bar spacing element,

Figure is a fragmentary vertical sectional View showing the coaction of the rake and wiper element,

Figure 11 is a fragmentary vertical sectional view showing the coaction of the rake cams and deflector plate, and

Figure 12 is a vertical sectional view of a modied form of trash screen embodying the invention.

In the drawings, wherein for the purpose of illustration is shown the preferred embodiment of this invention, and first particularly referring to Figs. 1 to 5, inclusive, there is shown a screen housing I2 encasing the upper part of the screen structure. The housing I2 bridges a channel I3, through which the water to be screened flows, and rests upon a foundation I4 forming a portion of the channel walls. Side walls I5 of the housing, on opposite sides of the channel I3, are provided with angle iron bases I6 which rest upon and are connected to the foundation I4. The downstream or back wall i8 of the housing is provided with an angle iron base I9 spanning the channel I3 and having its end portions resting upon the foundation I4. The back wall I8 and the side walls I5 have their adjacent vertical edges connected by angle irons 2|. The lower portion of the back wall I8 is provided with an access opening normally covered by a door 22 which is mounted on hinges 23 and maintained in its closed position by a latch mechanism 24.

A drive unit supporting platform 25 is welded, or otherwise suitably connected, to the upper portion of the 'back wall I8 and projects horizontally outwardly therefrom.

The upstream or front wall 26 of the housing is provided with an angle iron base 2'! similar to that of the back wall I8. however, projects forwardly from the upstream edges of the side walls I5 to form an overhanging portion 28 on the housing I2. This overhanging portion 28 provides in its lower portion a screening pan 29 and encases a portion of the wiper mechanism 3I which will be more fully described in a later paragraph.

The upper edges of the front, back and side walls, 26, I8, and I5, respectively, are flanged outwardly at 32 for connection to the opposing flanges 33 on the front top section 34 and rear top section 35 of the housing I2. The front and rear top sections 34 and 35, respectively, are fastened together and to the flanges 32 of the walls of the housing by bolts 36 which may be removed to provide access to the upper portion of the interior of the housing I2.

The foundation I4 is offset both downwardly and outwardly from the channel I3 so that a stepped increase in the depth of the channel occurs beneath the housing I2. As illustrated in Figs. 2, 3, and 5 to 8, inclusive, the step 3l in the bottom of the channel I3 receives the similarly stepped base plate 38 of the unitary bar rack 39. The base plate 38 is securely anchored to the step 31 by bolts 4I. Vertical side plates 42 are welded or otherwise suitably connected to the opposite ends of the base plate 38 and are anchored to concrete shoulders 43 on the side walls of the channel I3 by bolts 44 which engage the notched lugs 45 on the upstream edges of the side plates. The notches in the lugs 45 permit vertical movement of the bar rack 39 into and out of its position in the channel The front wall 26,

I3 after the anchor bolts 4I and 44 have been set into the foundation I4.

A plurality of vertical screen bars 46 are arranged in horizontally spaced relationship between the side plates 42 with their lower end surfaces resting upon the lower horizontal surface of the stepped base plate 38 and the upstream edges at their lower end portions engaging the vertical surface of the base plate. Spacing blocks 41 are positioned between the lower end portions of the bars 45, and are clamped between the plates 48 and 38 by bolts 49. The bars, therefore, extend vertically upwardly from the base plate with each bar supporting its own weight. Further rigidity is afforded the screen bars 46 and spacer blocks 41 `by the bolts 5I extending laterally through the side plates 42 and the bars and blocks. An inclined deecting plate 52 is mounted on the base plate 38 on the upstream side of and adjacent to the screen bars 46 to prevent the formation of a pocket for refuse along the lower edge of the bar rack 39.

The upper end portions of the side plates 42, best illustrated in Figs. 2 and 5, are supported in xed spaced relationship by the angle iron 53 which is connected therebetween. rFhe free upper end portions of the screen 'bars 46 are maintained in proper spaced relationship across the width of the channel by a bar spacer plate 54 having fingers 55 normally positioned between the adjacent screen bars. The end fingers 55 of the plate 54 are provided with wear plates 55a on their bottom surfaces. As illustrated in Figs. 2, 5 and 9, the spacer plate 54 is mounted for pivotal movement on a shaft 56 which is supported at its end portions by the bearings 51 which are, in turn, supported by brackets 58 located at the opposite sides of the channel I3. Pivotal movement of the spacer plate 54 toward a horizontal position is limited by a stop 59 extending across the channel I3 to engage the spacer plate when the ngers 55 are in their proper position between the screen bars 46. The ngers 55, however, may be freely moved from betweenthe bars 46 'by pivotal movement of the plate 54 toward a vertical position and will be returned to the proper position between the bars by gravity, as will be further described in a later paragraph.

Refuse collected from the water flowing in the channel I3 by the bar rack 39 is cleaned from the bars by rakes 6I mounted on and carried by a pair of endless chains 62, which are mounted for travel through paths extending downwardly from adjacent the opposite sides of the housing I2 into the outwardly offset portions 63 in the side walls of the channel I3 provided by the foundation I4. Each of the chains 62 is supported by a head sprocket wheel 64 in the upper portion of the housing I2 and a foot sprocket wheel 65 in the outwardly offset portion 63 near the lbottom of the channel I3. 'The head sprocket wheels 64 are keyed to a head shaft 66 having its opposite end portions supported by take-up bearings 61 which are mounted on the flanges 32 of the side walls I5 of the housing. A driven sprocket wheel 68 is keyed to one end of the head shaft 66 externally of the housing I2 and is drivingly connected by a chain 69, or the like, to the sprocket wheel 'I0 of a speed reducer 'II mounted on the drive supporting platform 25. The speed reducer 1I is, in turn, driven by a motor 'I2 through a coupling device 13. A drive guard 'I4 is mounted on the housing I2 to encase the sprockets 58 and 1I) and the chain 69.

The "foot sprocket Awheels 65' "rotate on 'affixed foot shaftl which is'supportedatits .opposite end portions by "bearings T6 vanchored to the foundation "lby the `bolts 11. l.'Ihe active runs of the chains travel'in Aan upward direction from the foot shaft sprocketjwheels 65 'to 'the head shaft'sprocket wheels, as indicated. by

the arrows A in Fig. 2, Vsothatthefralzes'ilil :will

mesh with the screen 'bars 46 andtravelupwardlytherealong for the `entire llengths of th'e'bars.

'The chains 62A are supportedforvertical travel .through their active runs bythe/chain guides "lil and through Dtheir return runs4 `by the chain guides 19, as is bestillustrated ,infFigsfZjand 4. 'The fakes 6 l are provided withfingers^8l properly spaced to coincide withthe spaces between the rack bars '45 while `passing upwardly along 'the' downstreamV surfaceof the bary rack 359. The

-base of the fingers 8l to prevent the refuse collected from spilling oif the'back of the rake.

Cam plates 9,3 are suitably connected to` Athe opposite ends of the rakes 6l in such a manner as to extend into the spaces between the side plates l2 and the rside walls ofthe channel i3 when the rakes are-moved upwardly along the downstream side of the bar rack 39. The cam plates `83, therefore, vcooperate with the side plates 42 to guide the rakes 6I. The side plates i2 also protect the Vcams and chains from any screenings which pass through the bars. The shape and additional functions of the cam plates 83 will be further discussedin a later paragraph. Lugs 84 are welded to the outer surfaces of the cam plates 33 for connecting theV rakes 5I to special attachment links 85 in the chains 62, as illustrated in Figs. 4, 5 and 7. A trip lug 86 also is mounted on each of the cam plates '83 at one end of each rake. The trip lugs 8B engage the operating lever 81 of the limit switch B8 mounted on the back wall 22 `of the housing near one side thereof. The limit switch 88 is operatively associated with the motor 12 through wiring, not shown, in such a manner as to prevent discontinuation of operation of the motor while leither of the rakes 6l is submerged in the water flowing through the channel I3.

As isbest illustrated in Fig. 2, the chains 62, in passing through their active run, will carry the rakes 5I through the position normally occupied by the bar spacer plate 54. As illustrated in Fig. 9, the vertical movement of each rake 6| and its cam plates B3 will move the arcuate camming surfaces i139 of said plates into engagement with the wear plates 55a on the fingers 55 of thel bar spacer plate 54. This position is illustrated in the full1ine drawing of Fig. 9. Further upward movement or the rake 6l and its attached cam plates 53 will cause pivotal movement of the bar spacer plate 54 to disengage'its fingers 55 from between the rack bars 46, as illustrated in the broken line drawing of Fig. '9. 'At .this time, the fingers iii of the rake '6l will afford lateral support 'for the upper'end portions of 'the rack bars 46 to replace the lateral support normally afforded by the *bar spacer plate "54. As the rake Bi continues yto lmove toward the weer ends 0f. thexsren bars-'45 the engel@ l"camming surfaces '691i `AVof ithercamplates Q3-will @75 'move-past theputer-ends@ffthe wear plates 55a on athe fingers "-55 `of-*the "bawspacerplate P54 to permit "the ba-r spacer plateto gradually return to its normal positionunder the force` of `gravity. The 4upperend portions of the screenlbars `i146 are, therefore, continuously maintained f in `-the properly spacedrelations'hip Veither bythe spacer plate 54 oir-bythe rakesl.

Referring once again toF-i'g. 2,it willf'bes'een that -as 1 each rake (i I approaches i thev upperL ends of the screen bars 46y the arcuate'cammingfsurfaces 92 of the cam plates 83 will be carried into engagement wi-th wea'rplates'93on the 'deflector 4plate i 9'4 which is fmou-nted or pivotal movement `'bythe shaft 95. When-in-its'normal-positiom-as illustrated in the lfull-lines of Fig. 11,the free edge portion of the deilecto'replate 94 restsupon stops 99 at the? bottom edge' ofthe xedplate 91. As the cam plates move upwardly, fhowever,

the deilector plate'9'4 will swing upwardlyfr'om l its normal position to the iposition illustrated 'by the broken-lines of Figjll.

As the upward movement of the `rake `tl continues, the angular camming surfaces 199 will move -past the ends of the wear plates 93, yas :illustrated in Fig. 2, to permittheldeflector-.plate 94to gradually return toits lrlormalp'csition under the force of-gravity. .The rake Bids-thereby cut off fromthe channel '15 so thatlanyrefuse Vsubsequently spilled or Lcleaned ffrom the :rake cannot be returned lto the channel i3. Further, fthe sloping deflectorplatef94pwhen in Lits normal position, will deiiect-any refuse`which-2i'sremoved or falls from thelrake vintothe .screenings pan 29 for'subsequentremovaland disposal.

During movementof the wearlplates 93alon'g the camming surfaces 98tor1returnthedelector plate 94 to itsnormal position, thezinclinedlupper surface of 'the angleiron82 `on ithe rake-ISI vwill contact the wiper blade I99 ofthe wiper :mechanism 3i ,i as illustratediinFig. 2. The wiper blade 99 `is carried bysa pair of leverarms `19| pivotally mounted on the .oppositesides Lof lthe housing l2 by brackets 102. The remaining'ends of thelever arms IGI are connectedbya weighted cross-brace |93 to 4partially lcounterbalance the weight ofthe wiperlblade. vWhenithe wiper :mechanism 3| `is in its normalfposition, the lever arms! 9| rest upon stops |04 whichlarelresilientlymounted on brackets fl05fon opposite sides of the housing I2. A `cam ffollower plate |05 is mounted on each .endof the wiper blade .99 vin alinement withthe path of'travel ofthe .cam plates 83 on the 'rakesBL As each rake I5! is moved upwardly into 'its position for permittingthe returnof thevdeector plate 94 to its normal position, the wiper blade 99 will move relatively downwardly lalong the inclined upper surface of the angle iron 92 on the rake. After the wiper-.bladel99 haslreached the edge `of the inclined surface of the angle iron 12B-2, as illustrated :by rthe full-.line drawing of Fig. 10, :and the' deflector plate "94 has returned to its lnormal"position,lurther movement ofthe rake El'will effect movement of the wiper blade :relatively downwardly along the vertical surface of theangle ironan'd laterally across ithe fingers 8l of therrake :6.1 towardtheir free en'd portions. This relative 4movement betweenthe wiper `blade 99 andthe rake-16| Vis illustrated in the broken -linesof Fig. 10. -Any--refuse-.car- `riedbythey rake `6I will thereby be scraped therefrom to drop onto lthe inclined sur-'face of lthe deflector plate i9`4ffor defiectionfinto fthe screenoff of the ends of the rake fingers 8| will permit the lower curved end portion of the cam follower plates |06 to drop into engagement with the arcuate camming surfaces 92 of the cam plates 83. Subsequently sliding engagement between the cam follower plates |06 and the camming surfaces 92 will bring the upper curved end portions of the cam follower plates into engagement with the angular camming surfaces 98 of the cam plates 83 to gradually return the wiper blade 99 to its normal position by gravity.

Referring now to Fig. 2 for a detailed description of the operation of the trash screen, it

readily will be apparent that water flowing along the channel I3 in the direction indicated by the arrow B will pass through the bar rack 39 to remove the heavier solids therefrom. The water contacting the chain 62, foot shaft 'I5 and its sprockets 65 will, therefore, be relatively free of any material which might jam the operation of the screen cleaning rakes 6I.

It also will be apparent that, depending upon the amount of refuse which will normally be removed from the water, the chains 62 may be driven by the motor 'I2 either continuously or intermittently at variable intervals and for varying periods. Further, the number of rakes 6I carried by the chains 62 may be increased or decreased to meet the particular requirements of various screen installations.

Considering now the movement of the rakes 6I when the motor 'I2 is actuated to drive the chains 62, it will be seen that the rakes are carried downwardly toward the bottom of the channel I3 by the inactive runs of the chains as indicated by the arrows C. Upon reaching the foot sprocket wheels 65, the direction of movement of the chains 62 is reversed with the result that the rakes 6I are successively brought into engagement with the screen bars 46 near their lowermost end portions, as indicated by the broken lines of Fig. 2. The fingers 8I of the rakes intermesh with and project beyond the rack bars 46 at this point to engage and lift from the channel I3 the refuse accumulated on the up-stream side of the bar rack. It is to be noted that the rack bars 46 are at all times supported at their lower end portions only, the spaces between the bars being maintained uniform by the bar spacer plate 54 and the rake fingers 8l, as has been previously described.

The vertical movement of the rakes 6I along the active run of the chains 62 will carry each rake successively into the positions normally occupied by the bar spacer plate 54, the pivoted deflector plate 94 and the wiper mechanism 3|, as has been previously described in detail. The refuse removed from the rakes 6I by the wiper mechanism 3|, after dropping onto the inclined deiiector plate 94 for deflection into the screenings pan 29, is periodically removed from the pan and disposed of in any desired manner.

The association between the limit switch 88 and the motor i2 is such that, when it becomes desirable to stop the operation of the cleaning mechanism, the switch operating lever 81 must iirst be engaged by the cam plate 83 at the end of one of the rakes 6I. By this arrangement, neither of the rakes 6I can remain submerged to restrict the flow of water in the channel I3 during those periods in which the rakes are not being moved.

The modification of the invention illustrated in Fig. 12 diifersmaterially from that illustrated in Figs. 1 to 11, inclusive, only in that the screen housing I2 and the elements it encases have been vertically separated from the bar rack 39. Such vertical separation, of course, requires that the chains 62 be increased in length. Since the corresponding elements of both of these modifications of the invention are structurally identical, the reference characters applied to Figs. l to 11, inclusive, have been employed to identify the corresponding elements in Fig. 12. For that reason the structure disclosed in Fig. 12 need not be described in detail.

As illustrated in Figs. 2 and l2, the depth of the channel I3 below the level of the floor may vary considerably. It is, therefore, desirable for purposes of economy and standardization that trash screens be adaptable for use in channels of different depths with a minimum amount of modification. The only physical connection between the housing I2 and bar rack 39 being through the chains 62, and the channel walls, it will be apparent that the distance between the bar rack and housing may be varied as required with no material modication of the screen structure other than the lengthening' of the chains. The structure of Fig. l2 operates in the same manner as that of Figs. 1 to 11, inclusive.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, I claim:

1. A screen for removing solids from a stream of Water flowing through a channel, comprising a pair of vertical side plates mounted on the side walls of the channel, a plurality of spaced vertical rack bars arranged between said side plates and rigidly supported at their lower end portions only, spacer means pivotally mounted adjacent the upper end portions of said bars for movement into and out of the spaces between the bars to provide lateral support for said upper end portions, cleaning means mounted for movement through a closed path on the downstream side of the rack bars and extending from the lower end portions to a point above the upper end portions of said bars, said cleaning means having teeth adapted to extend through the spaces between the bars to lift the solids accumulated on the upstream side of said bars from the stream, means for moving said cleaning means, deecting means pivotally mounted for movement into and out of the path of travel of said cleaning means above the upper end portions of said bars, means coacting with said cleaning means for engaging and moving said spacer' and deflecting means while the cleaning means is moved through those portions of its path in which the spacer and defiecting means normally lie, and scraper means mounted above said deflecting means and actuated by movement of the cleaning means to scrape solids from the latter onto the deflecting means, said defiecting means directing the solids away from the path of said cleaning means.

2. A screen for removing solids from a stream of water flowing through a channel, comprising a pair of vertical side plates mounted on the side walls of the channel, a plurality of spaced vertical rack bars arranged between said side plates and rigidly supported at their lower end portions only, a spacer plate pivotally mounted adjacent acm-56s the upper end portions of said bars .and having fingers projecting from its edge portionfor movement into and out of the spaces between the bars to provide ylateral support'for said upper end portions, a rakel mounted on a plurality of endless chains for movement through` a closed path on the downstream side of said bars and extending from the lower end -portionsto -a point above the upper end portions of said bars, said rake having teeth adapted to extend through the spaces between the bars to lift solids accumulated on the upstream side of said bars Vfrom the stream, means for moving said rake through its-closed path, deflecting means pivotally mounted for movement into and out of the path of said rake above the upper end portionsof said Lbarsmeans vcoasting with said rake for engaging and 'moving said spacer plate and said deflecting means while the rake is `moved through those portions of its path in which the spacer plate and deilecting means normally lie, and scraper means mounted. above said deecting means and actuated by movement of the rake to scrape the solids from the latter onto thedeiiecting means, said deecting means directing the Vsolids away from the path of said rake,

3. A screen for removing solids from a stream of water llowing through a channel, comprising a pair of vertical side plates mounted on the side walls o the Achannel and having their downstream edge portions oisetfrom the walls of the channel, a plurality of spaced vertical rack bars arranged between said side `plates and rigidly supported at their lower end portions only, spacer `means pivotally mounted adjacent the upper end portions of said bars 'for movement into and out of the spaces between the bars to provide lateral support for said upper `end portions, cleaning means mounted for movement through a closed path on the downstream side of 'the rack 'bars and extending from the lower -end portions to a point above the upper end :portions of 'said bars, said cleaning means having teeth adapted to extend through'the spaces between the bars to lift the solids accumulated on the upstream side of said bars from the stream, means for moving said cleaning means, deiiecting means pivotally mounted for movement into and out of the path of travel of said cleaning means above the upper end portions of said bars, a pair of cams mounted on opposite ends of said cleaning means forentering the space between offset edge portions of said side plates and the walls of the channel to provide lateral support for the cleaning means during movement of the `latter along 'said rack bars, said cams Valso engaging and .moving said spacer and deecting means while the cleaning means is moved through those portions of its path in which the spacer and deflecting means normally lie, and scraper means mounted above said derlecting means and actuated by movement of the cleaning means to scrape the solids from the latter onto the deiiecting'means, said deiiecting means directing Vthe solids 'away/"from the Ipath .of said rake.

a. A screen for removing solids from a stream of water flowing through a channel, comprising a pair of vertical side plates mounted on the side walls on the channel and having their dov/nstream edge portions offset from the walls of the channel, a plurality of spaced vertical rack bars arranged between said side plates and rigidly supported at their lower end portions only, a spacer plate pivotally mounted adjacent the upper end portions of said bars and having iinlo gers projecting from its -edge portion `for movementinto `and outof the spaces between thebars to provide lateral support for said upper end portions, a rake mounted on a plurality of endless chains .tor movement through a closed path on the downstream side of said rack .bars and extending from the lower end portions to a point above the upper end portions of said bars, said rake having teeth adapted to .extend through the spaces between the bars to lift solids accumulatedV on the upstream side of said lbars from the stream, a motor for driving said chains to move the rake through its closed path, a deflecting plate-mounted for pivotal movement into and out of the path ot said rake above the upper end portions of said bars, a pair of cams mounted on opposite ends of said rake for entering the space between the onset edge portionsofsaid Sdeplates and the walls of the channel to provide lateral support for the rake during its movement along said bars, said cams also engaging and moving said spacer' and deflecting plates while the Vrake is moved through those portions of its path in which the spacer and deilecting plates normally lie, and a scraper .pivotally mounted above said -deflecting plate -and actuated by engagement with the rake for movement across said teeth 'to displace the solids from the latter onto 'the deiecting plate, .said deflecting plate directing the solids away from the path of the rake.

5. A screen for removing solids from a stream oi water owing through a channel, comprisingI a pair of vertical side plates mounted on lthe side walls of the channel, the upstream edge portions of said plates being in contact with and 'the downstream edge ,portions being spaced from the channel walls, a plurality of spaced'vertical rack bars arranged between said side plates and rigidly supported atftheir lower end portions only,

spacer means pivotally mounted adjacent the free upper end portions of said rack bars for movement into and out oi the spaces between the bars toprovide lateral .support 'for' their upper end portions, cleaning means mounted Yfoi" `vertical movement through the spaces between said bars, `means coacting Vwith said cleaning means -for movement through the spaces between 'the channel walls-andthe downstream edge portions of said -sideplates to guide said cleaning means while the Alatter is movedthrough the spacesbetween'said bars, and means for moving said cleaning means, movement of said Vcleaning means and Vits coasting guide means into engagement with said spacer .means effecting pivotal movement'of the latter out of the spaces between the bars.

6. A-screen for removing solids from a stream of water flowing through a channel, comprising a pair of vertical side plates mounted on the side walls of the channel, the upstream -edgelpor'tions of said plates being in contact with and the downstream edge portions being spaced -from the Achannel walls, a plurality of spaced'vertical rack bars arranged betweensaid side plates and rigidly supported at their lower end portions only, spacer means pivotally mounted adacent -the free upper end portions of said bars for movement into and out of the spaces between the bars to provide lateral support for their upper end portions, a rake mounted for vertical movement along the downstream side of said bars and having teeth projecting through the spaces between the bars, a pair of cams mounted on the opposite ends of said rake for movement through the spaces between the channel walls and the clownstream edge portions of said side plates to laterally guide the rake along the downstream side of said bars, and means for moving said rake, movement of said rake and its associated cams into engagement with said spacer means eiecting pivotal movement of the latter out of the spaces between the bars and movement of said rake and cams out of engagement with said spacer means permitting the latter to re-enter the spaces between the bars while the upper end portions of the bars are laterally supported by said rake.

7. A screen for removing solids from a stream of water iiowing through a channel, comprising a plurality of spaced vertical rack bars arranged laterally across the channel and rigidly supported at their lower end portions only, a spacer plate mounted for pivotal movement about an axis adjacent the downstream side of the free upper end portions of said bars and having separating fingers along one edge portion movable into the spaces between the rack bars by gravitationally actuated pivotal movement of the plate, said separating fingers providing lateral support for the upper end portions of -said rack bars when positioned therebetween, a rake mounted for vertical movement along the downstream side of said rack bars and having teeth projecting through the spaces between the bars,

a prime mover for moving said rake, and a pair l of cams mounted on the opposite ends of said rake for engaging and moving said spacer plate to remove the separating fingers from the spaces between the rack bars only while the rake is passing between the bars and the spacer plate and is laterally supporting the upper end p0rtions of said bars.

8. A screen for removing solids from a stream of water flowing through a channel, comprising a plurality of spaced vertical rack bars arranged laterally across the channel and rigidly supported at their lower end portions only, spacer means pivotally mounted adjacent the free upper end portions of said bars for movement into and out of the spaces between the bars to provide lateral support for their upper end portions, cleaning means mounted for vertical movement through the spaces between said rack barsy and means for moving said screen cleaning means, said spacer means being actuated by said cleaning means for movement out of the spaces between said rack bars only while the cleaning means is moved past the spacer means.

9. A screen for removing solids from a stream of water ilowing through a channel, comprising a plurality of spaced vertical rack bars arranged laterally across the channel and rigidly supported at their lower end portions only, a spacer plate mounted for pivotal movement about an axis adjacent the downstream side of the free upper end portions of said rack bars and having separating fingers along one edge portion movable into the spaces between the bars by gravitationally actuated pivotal movement of the plate, said separating fingers providing lateral support for the upper end portions of said rack bars when Cil positioned therebetween, cleaning means mounted for vertical movement through the spaces between said rack bars, and means for moving said cleaning means, movement of said cleaning means actuating said spacer plate for pivotal movement to remove said separating fingers from the spaces between the bars only while the cleaning means is moved past the spacer plate.

10. In a screen for removing solids from a stream of water flowing through a channel, the improvement which comprises a plurality of spaced vertical rack bars arranged laterally across the channel, means rigidly connecting only the lower end portions of said rack bars to the bottom of the channel, the remaining unsupported portions of said bars being capable of flexing relative to each other, and spacer means mounted at a fixed location adjacent the free upper end portions of said rack bars on one side of the screen for free movement into and out of the spaces between the bars from said one side of the screen to provide lateral support for their upper end portions.

1l. In a screen for removing solids from a stream of water flowing through a channel, the improvement which comprises a plurality of spaced vertical rack bars arranged laterally across the channel, a clamp rigidly connecting the lower end portions of said rack bars to the bottom of the channel, and a spacer plate pivotally mounted for movement about a xed axis adjacent the downstream side of the free upper end portions of said rack bars and having spaeing iingers along one edge portion freely movable into and out of the spaces between the bars to provide lateral support for their upper end portions.

12. A screen for removing solids from a stream of water fiowing through a channel, comprising a plurality of spaced rack bars arranged laterally across the channel and rigidly supported at their lower end portions only, spacer means mounted adjacent the free upper end portions of said rack bars for movement into and out of the spaces between the bars to provide lateral support for their upper end portions, cleaning means mounted for movement through the spaces between said bars, means for moving said cleaning means, and means for moving said spacer means out of the spaces between the bars only while the cleaning means is moved past the spacer means.

CHARLES J. BENNER, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,529,602 Maine Mar. l0, 1925 1,585,157 Lee May 18, 1926 2,078,127 Dalton Apr. 20, 1937 2,128,347 Briggs Aug. 30, 1935 2,128,348 Briggs Aug. 30, 1938 2,307,601 Nichols Jan. 5, 1943 2,335,573 Scott Nov. 30, 1943 2,379,615 Walker July 3, 1945 

